PTU-2000 Meteorological Thermo-Hygrometer
Description
The Model PTU-2000 is a complete precision pressure, ambient temperature, and humidity professional quality measuring system designed for the meteorologist, climatologist, or atmospheric scientist. It provides accurate and reliable measurements achieving an absolute accuracy of ± 0.2° C in measuring ambient temperature over the entire ± 50° C range, relative humidity accuracy of ± 2% and pressure accuracy of ± 0.03" Hg. The system consists of an aspirated double-shielded platinum resistance thermometer, polymer capacitance hygrometer sensor, and solid state pressure sensor.
Ambient temperature is highly variable in both time and space, and a single measurement reflects a limited space-time domain. Historically, techniques other than direct measurement of ambient temperature have provided support for the global warming issue, but precise knowledge of atmospheric ambient temperatures is a fundamental component to understanding the Earth's climatic mechanisms. As we continue collecting ambient temperature data for the climatological database, improvements in the basic measurement are required. While some of the problems of measuring ambient temperature cannot be easily eliminated, basic instrumental and observational errors in climatic temperature measurements can be reduced using the PTU-2000.
Features
High accuracy
Maximum sensor protection with double intake radiation shields plus canopy shade ring
Fully aspirated
Analog output
Reliable solid-state detection technology
Precision platinum resistance thermometer
Solid state pressure transducer
Low maintenance
PTU-2000 system
Applications
Professional grade meteorological stations
Educational institutions
Aviation weather systems
Agricultural
Mechanical Configuration
The PTU-2000 electronics are packaged in a weatherproof NEMA-type PVC enclosure. The radiation shields are manufactured with white UV-resistant materials. Electrical and mechanical components are designed to operate over a temperature span of ± 50° C. The system typically mounts two meters above the ground to a tower or support and aimed into the prevailing wind.
PTU-2000 sensor head.
Cross section identifying temperature sensor, double shielding, canopy shade ring, and air intake.
Detailed view of bottom of temperature sensor showing double intake radiation shields, canopy shade ring, and screen.
Electrical Connections
Two foil-shielded 10' (3m) long cables are supplied with pig tails for interface to the user's junction box:
DC power input; isolated return analog output
Power cable for + 12 Vdc
Twisted pair 4-20 mA or 0-1 Vdc for temperature
Twisted pair 4-20 mA or 0-1 Vdc for humidity
Twisted pair 4-20 mA or 0-1 Vdc for pressure
Available Options
Spare aspiration blower
Spare aspiration screen
Mechanical Interface, Dimensions in inches (cm)
| Specifications |
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Power Requirement 11-14 Vdc, 250 mA |
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Environmental Operating Range ±50ºC |
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Aspiration Rate Approximately 400 FPM |
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Dimensions 45.5" long x 8.0" wide x 12.5" high (115 cm x 20 cm x 31.7 cm) |
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Weight 4.5 lb (2.0 kg) |
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Temperature Measurement Type: Platinum resistance thermometer Measuring Range: +50ºC to -50ºC Accuracy: ±0.2ºC Analog Output: 1-5 Vdc |
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Humidity Measurement Type: Polymer capacitance Measuring Range: 0 to 100% RH Operating Temperature: +60ºC to -40ºC Accuracy: ±2% RH Stability: ±1% over 5 years Linearity: ±0.5% RH Hysteresis: ±1.2% of RH span maximum Repeatability: ±0.5% RH Response time: 15 sec in slowly moving air at 25ºC Analog Output: 1-5 Vdc |
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Pressure Measurement Type: Solid state Range: 1100 mb to 600 mb (32.50 to 17.70 in Hg) Operating Temperature: +60ºC to -40ºC Accuracy: ±0.3 mb (0.01 in Hg) at 20ºC ±1 mb (0.03 in Hg) over temperature range Analog Output: 1-5 Vdc |